Apparatus for Manufacturing Nanoporous Silica  Method Thereof

ABSTRACT

The present invention relates to an apparatus and a method for manufacturing amorphous nanoporous silica enabling mixing of source materials with accurate equivalence ratio by generating an eddy current using high-speed reaction nozzles and capable of controlling physical properties using a continuous circulation polymerizer which performs high-speed stirring and low-speed stirring and amorphous nanoporous silica prepared by the method, which has a BET surface area of 100-850 m 2 /g, a pore size of 2-100 nm and a pore volume of 0.2-2.5 mL/g.

TECHNICAL FIELD

The present invention relates to an apparatus and a method formanufacturing amorphous nanoporous silica enabling mixing of sourcematerials with accurate equivalence ratio by generating an eddy currentusing high-speed reaction nozzles and capable of controlling physicalproperties using a continuous circulation polymerizer which performshigh-speed stirring and low-speed stirring and amorphous nanoporoussilica prepared by the method.

BACKGROUND ART

Methods for manufacturing silica can be roughly classified into the wetprocess and the dry process. Gel type silica and precipitated silica canbe prepared by the wet process. Both the gel type silica and theprecipitated silica are prepared from sodium silicate (Na₂O.nSiO₂) andsulfuric acid (H₂SO₄). While the gel type silica is prepared by gelationin an alkaline condition with a relatively high silica concentration,the precipitated silica is precipitated as solid by stirring at arelatively low concentration. And, whereas the gel type silica can beprepared in both acidic and alkaline conditions, the precipitated silicacan be prepared only in an alkaline condition. Also, while themanufacturing process of the gel type silica requires a long reactiontime (20-80 hours) for gelation and grinding, the precipitated silicacan be prepared in a short time (1-5 hours) because it is precipitatedas the reaction proceeds.

In the conventional manufacturing process of precipitated silica (seeFIG. 4), sodium silicate and sulfuric acid are fed directly to thepolymerization tank equipped with a stirrer via different feed pipes. Inthis case, the region where the sulfuric acid is fed tends to be acidicand the region where the sodium silicate is fed tends to be alkalineand, consequently, the equivalence ratio of the sulfuric acid and thesodium silicate inside the reactor varies depending on the location.

Thus, control of the equivalence ratio of the sodium silicate and thesulfuric acid becomes difficult and it is impossible to obtainnanoporous silica with uniform physical properties. It is because pH isthe most important factor that affects coagulation, growth and gelationof Si(OH)₄ particles formed by acidic decomposition of sodium silicate(The Chemistry of Silica; Ralph. K. Iler, John Wiley and Sons, New York,p. 177-200, 1979.). The pH at the moment when sodium silicate andsulfuric acid contact each other is a very important factor incontrolling the physical properties of nanoporous silica. FIG. 6 showsthe gelation time (gel time) required for the silica sol having a lot ofsilinol groups (—Si—OH), which is formed at the early stage, to betransformed into solid during the wet process of silica manufacturing.When the pH is in the range from 0 to 2, the gel time is longer becauseof increased sol stability. The gel time is longest at pH 2, or theisoelectric point of silica, where it is the most stable. In the regionwhere the pH is from 2 to 6, the gel time decreases as the sol stabilitydecreases and increases again from pH 6 as the stability of silica solincreases.

If sodium silicate and inorganic acid are fed via different feed pipes,as in the conventional manufacturing process of precipitated silica, itis difficult to control the pH of each site at each moment. As a result,formation of 3-4 nm sized primary particles and transformation into the3-dimensional network structure are changeable at every minute, andthus, control of the physical properties and morphology of thenanoporous silica is impossible. Also, it is impossible to attainuniform physical properties with the conventional manufacturing processof precipitated silica when the reaction is performed at high speed,because the pH changes abruptly inside the reactor.

As for gel type silica, additional washing and drying processes arerequired following the transfer and grinding of the obtained wet gel. Ingeneral, it takes about 20-40 hours for the washing.

The conventional nanoporous silica, gel type silica and precipitatedsilica altogether, is manufactured in batch type. No matter how closelythe process is controlled, variation in physical properties from onebatch to another is inevitable. Thus, manufacturing of conventional geltype silica and precipitated silica has its limits. For example, KoreanPatent No. 0244062 discloses a manufacturing method of nanoporous silicacomprising the steps of: i) preparing an initial mother liquorcomprising less than 100 g/L of silicate and less than 17 g/L ofelectrolytes, ii) adding an acidulator to the mother liquor until the pHof the reaction mixture becomes about 7 or higher and iii)simultaneously adding an acidulator and silicate to the reactionmixture. However, when an acidulator and silicate are simultaneouslyadded to the reactor containing the mother liquor, locally non-uniformequivalence ratios are created during the mixing with the mother liquor.According to the silica polymerization theory as depicted in FIG. 6,different pH's result in different polymerization rates and differentformation patterns of primary particles. Therefore, there can be somevariation in physical properties of the nanoporous silica of differentbatches at all times.

DISCLOSURE OF THE INVENTION

To solve the problem, the present inventors developed an apparatus formanufacturing amorphous nanoporous silica comprising a high-speedinstantaneous reactor, which is equipped with nozzles that generate aneddy current of the source materials for them to be mixed with anaccurate equivalence ratio, and a high-speed/low-speed stirringcontinuous circulation polymerizer, which enables uniform control ofphysical properties.

Thus, it is an object of the present invention to provide an apparatusfor manufacturing amorphous nanoporous silica comprising a sourcematerial feeder equipped with fluctuation-proof air chambers, ahigh-speed instantaneous reactor equipped with nozzles and a continuouscirculation polymerizer that offers high-speed stirring and low-speedstirring following the reaction for uniform physical properties.

It is another object of the present invention to provide a method formanufacturing amorphous nanoporous silica having uniform physicalproperties with a BET surface area of 100-850 m²/g, a pore size of 2-100nm and a pore volume of 0.2-2.5 mL/g and amorphous nanoporous silicamanufactured by the method.

To attain the objects, the present invention provides an apparatus formanufacturing amorphous nanoporous silica comprising: a source materialfeeder composed of a quantitative silicate feeder, a quantitativeinorganic acid feeder, quantitative pumps that control the equivalenceratio of silicate and inorganic acid and fluctuation-proof air chambersthat control the fluctuation generated by the quantitative pumps; ahigh-speed instantaneous reactor which is connected to the sourcematerial feeder and is equipped with nozzles that generate an eddycurrent of the silicate and the inorganic acid; and a continuouscirculation polymerizer which is connected with the high-speedinstantaneous reactor and is composed of a high-speed stirring reactiontank with a maximum stirring rate of 100 to 20000 rpm, a low-speedstirring reaction tank that offers a stirring at 10 to 100 rpm and acirculation pump that offers a continuous circulation for the high-speedstirring reaction tank and the low-speed stirring reaction tank.

The present invention also provides a method for manufacturing amorphousnanoporous silica comprising: a source material feeding step of feedingthe source materials, i.e., silicate and inorganic acid, usingquantitative feeders while controlling the fluctuation associated withthe source material feeding; a high-speed instantaneous reaction step ofgenerating an eddy current of the supplied silicate and inorganic acidusing nozzles; and a continuous circulation polymerization step ofstirring the resultant silica sol at a high rate of 100 to 20000 rpm andstirring the resultant nanoporous silica at a low rate of 10 to 100 rpmfor the control of physical properties.

The present invention further provides amorphous nanoporous silica whichis prepared by the afore-mentioned method and has a BET surface area of100-850 m²/g, a pore size of 2-100 nm and a pore volume of 0.2-2.5 mL/g.

Hereunder is given a more detailed description of the present invention.

The apparatus for manufacturing nanoporous silica of the presentinvention comprises a source material feeder equipped withfluctuation-proof air chambers, a high-speed instantaneous reactorequipped with nozzles and a continuous circulation polymerizer whichperforms high-speed and low-speed stirring following the reaction inorder to offer uniform physical properties. It further comprises afilter, a washer, a drier, a grinder and a classifier.

The quantitative pumps connected with the quantitative silicate feederand the quantitative inorganic acid feeder and capable of accuratelycontrolling the equivalence ratio of silicate and inorganic acid and thefluctuation-proof air chambers specially designed to accurately controlthe fluctuation generated by the quantitative pumps enable accurate andquantitative feeding of the source materials, i.e., the silicate and theinorganic acid, to the high-speed instantaneous reactor. The silicateand the inorganic acid are fed, at a pressure of at least 0.5 kg/cm², tothe nozzles inside the high-speed instantaneous reactor, which aredesigned to generate an eddy current. The silicate may be sodiumsilicate, potassium silicate, lithium silicate, rubidium silicate orcesium silicate and the inorganic acid may be sulfuric acid,hydrochloric acid, phosphoric acid, acetic acid, perchloric acid,chloric acid, chlorous acid, hypochlorous acid, citric acid or nitricacid. The eddy current generated by the nozzles enables instantaneousmixing of the silicate and the inorganic acid, thereby enablingformation of uniform primary particles and making it easier to controlthe physical properties of the secondary particles formed by coagulationof the primary particles. The injection speed of the nozzles can becontrolled with the feed rate of the quantitative pumps or with thediameter of the nozzles.

The pH and temperature of the continuous circulation polymerizer arecontrolled as follows. When manufacturing nanoporous silica having asurface area of 500 m²/g or larger, the pH is adjusted to the acidiccondition of pH 2-5 and the temperature is controlled relatively low at40° C. or below. And, when manufacturing nanoporous silica having asurface area smaller than 500 m²/g, the pH is adjusted to the basiccondition of pH 7-9.5 and the temperature is controlled relatively highat 50-90° C. The continuous circulation polymerizer is equipped with acirculation pump, between the high-speed stirring reaction tank thatoffers a stirring at 100 to 20000 rpm and the low-speed stirringreaction tank that offers a stirring at 10 to 100 rpm, which offers acontinuous circulation, thereby offering uniform, ideal physicalproperties in a short period of time. The high-speed stirring reactiontank is used to maintain overall uniformity and the low-speed stirringreaction tank is used to control the polymerization rate of silica bycontrolling the temperature and pH. Thus, without the high-speedstirring reaction tank or the low-speed stirring reaction tank, it isimpossible to stir a large amount of silica at high rate.

When the polymerization process is completed, the silica isautomatically transferred to a storage tank for filtering by the 3-wayvalve installed at the bottom of the low-speed stirring reaction tank.Salt ions included in the nanoporous silica or in the solutioncontaining the silica are removed by a filter press to give nanoporoussilica hydrogel, which may be the final product or may be dried toobtain xerogel or aerogel. Also, it may be further grinded to obtainfiner particles. The resultant products are hydrophilic, but they may betransformed hydrophobically using a surface modifier.

As described above, the apparatus for manufacturing nanoporous silica inaccordance with the present invention enables accurate control of theequivalence ratio of source materials using fluctuation-proof airchambers, offers quantitative instantaneous reaction using high-speedreaction nozzles and enables mass production of nanoporous silica withuniform physical properties in short time by continuous circulationpolymerization. Also, it reduces time required for filtering and washingfollowing the polymerization, and thus saves production cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the overall manufacturing process of nanoporoussilica in accordance with the present invention.

FIG. 2 illustrates the transfer of the source materials from thequantitative feeders to the high-speed instantaneous reactor.

FIG. 3 illustrates the specific construction of the high-speedinstantaneous reactor.

FIG. 4 illustrates the conventional manufacturing process ofprecipitated silica.

FIG. 5 illustrates the conventional manufacturing process of gel typesilica.

FIG. 6 shows the effect of pH on colloidal silica in water.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the present invention is described in further detail referring tothe attached drawings.

FIG. 1 illustrates the overall manufacturing process of nanoporoussilica in accordance with the present invention. The source materials,silicate and inorganic acid, supplied to each quantitative feeder (1,1′) are transferred to fluctuation-proof air chambers (3, 3′) forpreventing the fluctuation caused by the silicate and the inorganic acidand uniformly fed to the high-speed instantaneous reactor (4). Thesilica sol emerging from the high-speed instantaneous reactor (4) passesthrough the high-speed stirrer (5) that offers a high-speed stirring atabout 100-20000 rpm for more uniform control of the equivalence ratioand is transferred to the low-speed stirrer (6) that offers a low-speedstirring at about 10-100 rpm for polymerization. The circulation pump(7) offers a continuous circulation between the high-speed stirrer andthe low-speed stirrer, and thus perfectly uniform nanoporous silica. Thenanoporous silica particles, physical properties of which have beencontrolled by the low-speed stirrer, is re-circulated to the high-speedstirrer via the 3-way valve (8) or transferred to the storage tank (10)via the evacuation valve (9).

FIG. 2 illustrates the transfer of the source materials from thequantitative feeders to the high-speed instantaneous reactor. Thesilicate and the inorganic acid supplied to the quantitative feeder arefed to the high-speed instantaneous reactor (4) equipped with thenozzles (14) passing through the quantitative pumps (2, 2′) and thefluctuation-proof air chambers (3, 3′) at a uniform equivalence ratio.The high-speed reaction nozzles generate an eddy current of the silicateand the inorganic acid for accurate, instantaneous, quantitative mixing.

FIG. 3 illustrates the specific construction of the high-speedinstantaneous reactor. The silicate and the inorganic acid are fed toeach feed section (21, 21′) at a controlled flow rate and a pressure ofat least 0.5 kg/cm². A liquid is uniformly injected at eachspiral-shaped eddy current generating section (22, 22′). The eddycurrent of the silicate and the eddy current of the inorganic acidcontact each other equivalently at the complete mixing section (23). Thesilicate and the inorganic acid are mixed uniformly once again by theeddy current there, evacuated at the evacuation section (24) located atthe end of the nozzles and transferred to the continuous circulationpolymerization reactor equipped with a high-speed stirring reaction tankand a low-speed stirring reaction tank.

FIG. 4 illustrates the conventional manufacturing process ofprecipitated silica. Since silicate and inorganic acid are fed fromoutside into a large polymerization tank, without special control,equivalence ratio and pH distribution at the site where the silicate andthe inorganic acid are supplied are always non-uniform. Thus, it isrequired to perform the reaction for a long time with a small amount ofsource materials in order to obtain uniform physical properties, whichis also limited in practice.

FIG. 5 illustrates the conventional manufacturing process of gel typesilica. The bulk type wet gel formed from the reaction of silicate andinorganic acid is transferred to a wash tank, where it is washed withwater for 20 to 60 hours of a long time. The long washing time and thecomplicatedness in transfer make automation difficult. Thus, this methodis limited to be applied for mass production. Besides, the resultantsilica has to be grinded to obtain powder.

The manufacturing process of nanoporous silica in accordance with thepresent invention can solve the problem of non-uniform physicalproperties of the conventional method, which results from non-uniformcontrol of the equivalence ratio of silicate and inorganic acid andlocal difference in pH. Also, the reaction time can be reduced. Since,the silicate and the inorganic acid fed by the source material feederreact with each other quickly and are transferred to the continuouscirculation polymerizer that offers high-speed stirring and low-speedstirring, productivity per unit facility is improved and mass productionof products with uniform physical properties is possible. Whereas theconventional method required a polymerization time of 5 hours or more,the method of the present invention requires as little as 2 hours oftime. And, whereas the conventional method is limited in manufacturingprecipitated silica with a surface area of 150-400 m²/g or larger, thepresent invention can manufacture offer a surface area of up to 150-850m²/g. Thus, the precipitated silica prepared by the present inventioncan be utilized in a variety of applications, including plastics,paints, pigments, protein removers, toothpaste abrasives, thixotropicagents and catalyst supports.

Besides, the present invention reduces the polymerization time, which is20-80 hours in the conventional manufacture of gel type silica, to lessthan 10 hours, while offering the physical properties of the gel typesilica. In addition, the resultant silica can be easily prepared intopowder without forming a lump.

Hereinafter, the present invention is described in further detailthrough examples. However, the following examples are only for theunderstanding of the present invention and they are not to be construedas limiting the present invention.

Example 1

Sodium silicate with a SiO₂/Na₂O molar ratio of 3.4 and a solid contentof 210 g/L and 110 g/L of sulfuric acid solution were used. Reaction wasperformed using a high-speed instantaneous quantitative continuousreactor. In order to prevent fluctuation generated by the quantitativepumps, the air pressure inside the air chambers was adjusted to 0.5kg/cm² before feeding sodium silicate and sulfuric acid. Aftercontravening that the fluctuation had been controlled and the sourcematerials were feed constantly with time, an eddy current of the sodiumsilicate and sulfuric acid were generated at the high-speedinstantaneous reactor equipped with nozzles for instantaneousquantitative mixing. The equivalence ratio of sodium silicate andsulfuric acid was adjusted with a torque control lever attached to thequantitative pumps to pH 6. The reaction mixture was stirred at 200 rpmin the continuously connected high-speed stirring reaction tank andtransferred to the low-speed stirring reaction tank by free falling andoverflow. At the same time, the reaction mixture was continuouslycirculated by a circulation pump located between the low-speed stirringreaction tank and the high-speed stirring reaction tank, in order tooffer uniform physical properties. Water was continuously supplied tothe low-speed stirring reaction tank in order to control the solidcontent of silica, so that the concentration of silica was maintained at15 g per a liter of water. The pH inside the low-speed stirring reactiontank was controlled at pH 3-5 and the temperature was maintained at 40°C., while continuously stirring at about 60 rpm. The stirring wasperformed for 30 minutes.

The reaction mixture was transferred to the filter press located atbelow the low-speed stirring reaction tank via a 3-way automatictransfer. Sulfate ion and sodium ion present within the nanoporoussilica were washed away with 25° C. of water. When the pH of the washingwater reached about pH 6.5-7.5, washing was stopped and the resultantnanoporous silica slurry was dried with a spray drier at 300° C. Theobtained nanoporous silica had an almost spherical bead shape. For themeasurement of the DBP absorption of the nanoporous silica, 100 mL ofdried DBP sample was grinded to a size below 325 mesh by ISO 787/V.Consumption of DBP oil for 10 g of the sample was interpreted asendpoint. The DBP absorption was computed as 103 mL/100 g. BET surfacearea was measured by the Brunauer-Emmet-Teller process (Journal of theAmerican Chemical Society, vol. 60, p. 309, February 1938.) using ameasurement device (Micrometrics ASAP 2400). The measurement was carriedout up to 5 points after pre-treatment by taking 0.08 g weight ofsample. As a result, the BET surface area was 750 m²/g, the pore sizewas 2.04 nm and the pore volume was 0.4 mL/g.

Example 2

Sodium silicate with a SiO₂/Na₂O molar ratio of 3.4 and a solid contentof 233 g/L and 135 g/L of sulfuric acid solution were used. Reaction wasperformed using a high-speed instantaneous quantitative continuousreactor. In order to prevent fluctuation generated by the quantitativepumps, the air pressure inside the air chambers was adjusted to 0.5kg/cm² before feeding sodium silicate and sulfuric acid. Aftercontravening that the fluctuation had been controlled and the sourcematerials were feed constantly with time, an eddy current of the sodiumsilicate and sulfuric acid were generated at the high-speedinstantaneous reactor equipped with nozzles for instantaneousquantitative mixing. The equivalence ratio of sodium silicate andsulfuric acid was adjusted with a torque control lever attached to thequantitative pumps to pH 8.5.

The reaction mixture was stirred at 400 rpm in the continuouslyconnected high-speed stirring reaction tank and transferred to thelow-speed stirring reaction tank by free falling and overflow. At thesame time, the reaction mixture was continuously circulated by acirculation pump located between the low-speed stirring reaction tankand the high-speed stirring reaction tank, in order to offer uniformphysical properties. Water was continuously supplied to the low-speedstirring reaction tank in order to control the solid content of silica,so that the concentration of silica was maintained at 25 g per a literof water. The pH inside the low-speed stirring reaction tank wascontrolled at pH 9.5 and the temperature was maintained at 90° C. Thereaction mixture was stirred continuously at the rate 60 rpm for 50minutes.

The reaction mixture was transferred to the filter press located atbelow the low-speed stirring reaction tank via an 3-way automatictransfer. Sulfate ion and sodium ion present within the nanoporoussilica were washed away with 95° C. of water. When the pH of the washingwater reached about pH 7-8, washing was stopped and the resultantnanoporous silica slurry was dried with a spray drier at 300° C. Theobtained nanoporous silica had an almost spherical bead shape. For themeasurement of the DBP absorption of the nanoporous silica, 100 mL ofdried DBP sample was grinded to a size below 325 mesh by ISO 787/V.Consumption of DBP oil for 10 g of the sample was interpreted asendpoint. The DBP absorption was computed as 220 mL/100 g. BET surfacearea was measured by the Brunauer-Emmet-Teller process using ameasurement device (Micrometrics ASAP 2400). The measurement was carriedout up to 5 point after pretreatment by taking 0.09 g weights of sample.As a result, the BET surface area was 250 m²/g, the pore size was 10.2nm and the pore volume was 0.9 mL/g.

Example 3

Sodium silicate with a SiO₂/Na₂O molar ratio of 3.4 and a solid contentof 270 g/L and 145 g/L of sulfuric acid solution were used. Reaction wasperformed using a high-speed instantaneous quantitative continuousreactor. In order to prevent fluctuation generated by the quantitativepumps, the air pressure inside the air chambers was adjusted to 0.5kg/cm² before feeding sodium silicate and sulfuric acid. Aftercontravening that the fluctuation had been controlled and the sourcematerials were feed constantly with time, an eddy current of the sodiumsilicate and sulfuric acid were generated at the high-speedinstantaneous reactor equipped with nozzles for instantaneousquantitative mixing. The equivalence ratio of sodium silicate andsulfuric acid was adjusted with a torque control lever attached to thequantitative pumps to pH 7.5.

The reaction mixture was stirred at 200 rpm in the continuouslyconnected high-speed stirring reaction tank and transferred to thelow-speed stirring reaction tank by free falling and overflow. At thesame time, the reaction mixture was continuously circulated by acirculation pump located between the low-speed stirring reaction tankand the high-speed stirring reaction tank, in order to offer uniformphysical properties.

Water was continuously supplied to the low-speed stirring reaction tankin order to control the solid content of silica, so that theconcentration of silica was maintained at 20 g per a liter of water. ThepH inside the low-speed stirring reaction tank was controlled at pH 8.5and the temperature was maintained at 90° C., while continuouslystirring at about 60 rpm. The stirring was performed for 110 minutes.

The reaction mixture was transferred to the filter press located atbelow the low-speed stirring reaction tank via an 3-way automatictransfer. Sulfate ion and sodium ion present within the nanoporoussilica were washed away with 90° C. of water. When the pH of the washingwater reached about pH 7-8, washing was stopped and the resultantnanoporous silica slurry was dried with a spray drier at 300° C. Theobtained nanoporous silica had an almost spherical bead shape. For themeasurement of the DBP absorption of the nanoporous silica, 100 mL ofdried DBP sample was grinded to a size below 325 mesh by ISO 787/V.Consumption of DBP oil for 10 g of the sample was interpreted asendpoint. The DBP absorption was computed as 320 mL/100 g. BET surfacearea was measured by the Brunauer-Emmet-Teller process using ameasurement device (Micrometrics ASAP 2400). 0.09 g was weighed andmeasurement was made up to 5 points after pre-treatment. As a result,the BET surface area was 330 m²/g, the pore size was 12.5 nm and thepore volume was 1.25 mL/g.

Table 1 below shows the manufacturing condition and physical propertiesof the nanoporous silica prepared in Examples 1 to 3.

TABLE 1 Example 1 Example 2 Example 3 Silicate concentration (g/L) 210233 270 Sulfuric acid concentration 110 135 145 (g/L) pH after reaction6 8.5 7.5 Solid content of silica (g/L) 15 25 20 pH, low-speed stirring3-5 9.5 8.5 Temperature, low-speed 40 90 90 stirring (° C.) Reactiontime (min) 30 50 110 pH after wash 6.5-7.5 7-8 7-8 Temperature, washingwater 25 95 90 (° C.) DBF absorption (mL/100 g) 103 220 320 BET surfacearea (m²/g) 750 250 330 Pore size (nm) 2.04 10.2 12.5 Pore volume (mL/g)0.4 0.9 1.25

While the present invention has been described in detail with referenceto the preferred embodiments, those skilled in the art will appreciatethat various modifications and substitutions can be made thereto withoutdeparting from the spirit and scope of the present invention as setforth in the appended claims.

1. An for manufacturing amorphous nanoporous silica comprising: a sourcematerial feeder composed of a quantitative silicate feeder, aquantitative inorganic acid feeder, quantitative pumps that control theequivalence ratio of silicate and inorganic acid and fluctuation-proofair chambers that control the fluctuation generated by the quantitativepumps; a high-speed instantaneous reactor which is connected to thesource material feeder and is equipped with nozzles that generated aneddy current of the silicate and the inorganic acid; and a continuouscirculation polymerizer which is connected with the high-speedinstantaneous reactor and is composed of a high-speed stirring reactiontank with a maximum stirring rate of 100 to 20000 rpm, a low-speedstirring reaction tank that offers a stirring at 10 to 100 rpm and acirculation pump that offers a continuous circulation for the high-speedstirring reaction tank and the low-speed stirring reaction tank.
 2. Theapparatus of claim 1, wherein the manufactured nanoporous silica has aBET surface area of 100-850 m²/g, a pore size of 2-100 nm and a porevolume of 0.2-2.5 mL/g.
 3. The apparatus of claim 1, which furthercomprises a 3-way valve that is connected with the bottom of thelow-speed stirring reaction tank and circulates or evacuates thenanoporous silica whose physical properties are controlled by thelow-speed stirring reaction tank.
 4. The apparatus of claim 1, whereinthe silicate is selected from a group consisting of sodium silicate,potassium silicate, lithium silicate, rubidium silicate and cesiumsilicate.
 5. The apparatus of claim 1, wherein the inorganic acid isselected from a group consisting of sulfuric acid, hydrochloric acid,phosphoric acid, acetic acid, perchloric acid, chloric acid, chlorousacid, hypochlorous acid, citric acid and nitric acid.
 6. A method formanufacturing amorphous nanoporous silica comprising: a source materialfeeding step of feeding the source materials, i.e., silicate andinorganic acid, with quantitative feeders while controlling thefluctuation associated with the source material feeding; a high-speedinstantaneous reaction step of generating an eddy current of thesupplied silicate and inorganic acid using nozzles; and a continuouscirculation polymerization step of stirring the resultant silica sol ata high rate of 100 to 20000 rpm and stirring the resultant nanoporoussilica at a low rate of 10 to 100 rpm for the control of physicalproperties.
 7. (canceled)